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Diffstat (limited to 'src/concurrent/qtconcurrentexception.cpp')
-rw-r--r-- | src/concurrent/qtconcurrentexception.cpp | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/src/concurrent/qtconcurrentexception.cpp b/src/concurrent/qtconcurrentexception.cpp new file mode 100644 index 0000000000..caeaa8d9be --- /dev/null +++ b/src/concurrent/qtconcurrentexception.cpp @@ -0,0 +1,211 @@ +/**************************************************************************** +** +** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/ +** +** This file is part of the QtCore module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** GNU Lesser General Public License Usage +** This file may be used under the terms of the GNU Lesser General Public +** License version 2.1 as published by the Free Software Foundation and +** appearing in the file LICENSE.LGPL included in the packaging of this +** file. Please review the following information to ensure the GNU Lesser +** General Public License version 2.1 requirements will be met: +** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain additional +** rights. These rights are described in the Nokia Qt LGPL Exception +** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU General +** Public License version 3.0 as published by the Free Software Foundation +** and appearing in the file LICENSE.GPL included in the packaging of this +** file. Please review the following information to ensure the GNU General +** Public License version 3.0 requirements will be met: +** http://www.gnu.org/copyleft/gpl.html. +** +** Other Usage +** Alternatively, this file may be used in accordance with the terms and +** conditions contained in a signed written agreement between you and Nokia. +** +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qtconcurrentexception.h" +#include "QtCore/qshareddata.h" + +#ifndef QT_NO_QFUTURE +#ifndef QT_NO_EXCEPTIONS + +QT_BEGIN_NAMESPACE + +/*! + \class QtConcurrent::Exception + \brief The Exception class provides a base class for exceptions that can transferred across threads. + \since 4.4 + + Qt Concurrent supports throwing and catching exceptions across thread + boundaries, provided that the exception inherit from QtConcurrent::Exception + and implement two helper functions: + + \snippet doc/src/snippets/code/src_corelib_concurrent_qtconcurrentexception.cpp 0 + + QtConcurrent::Exception subclasses must be thrown by value and + caught by reference: + + \snippet doc/src/snippets/code/src_corelib_concurrent_qtconcurrentexception.cpp 1 + + If you throw an exception that is not a subclass of QtConcurrent::Exception, + the Qt Concurrent functions will throw a QtConcurrent::UnhandledException + in the receiver thread. + + When using QFuture, transferred exceptions will be thrown when calling the following functions: + \list + \o QFuture::waitForFinished() + \o QFuture::result() + \o QFuture::resultAt() + \o QFuture::results() + \endlist +*/ + +/*! + \fn QtConcurrent::Exception::raise() const + In your QtConcurrent::Exception subclass, reimplement raise() like this: + + \snippet doc/src/snippets/code/src_corelib_concurrent_qtconcurrentexception.cpp 2 +*/ + +/*! + \fn QtConcurrent::Exception::clone() const + In your QtConcurrent::Exception subclass, reimplement clone() like this: + + \snippet doc/src/snippets/code/src_corelib_concurrent_qtconcurrentexception.cpp 3 +*/ + +/*! + \class QtConcurrent::UnhandledException + + \brief The UnhandledException class represents an unhandled exception in a worker thread. + \since 4.4 + + If a worker thread throws an exception that is not a subclass of QtConcurrent::Exception, + the Qt Concurrent functions will throw a QtConcurrent::UnhandledException + on the receiver thread side. + + Inheriting from this class is not supported. +*/ + +/*! + \fn QtConcurrent::UnhandledException::raise() const + \internal +*/ + +/*! + \fn QtConcurrent::UnhandledException::clone() const + \internal +*/ + +namespace QtConcurrent +{ + +void Exception::raise() const +{ + Exception e = *this; + throw e; +} + +Exception *Exception::clone() const +{ + return new Exception(*this); +} + +void UnhandledException::raise() const +{ + UnhandledException e = *this; + throw e; +} + +Exception *UnhandledException::clone() const +{ + return new UnhandledException(*this); +} + +#ifndef qdoc + +namespace internal { + +class Base : public QSharedData +{ +public: + Base(Exception *exception) + : exception(exception), hasThrown(false) { } + ~Base() { delete exception; } + + Exception *exception; + bool hasThrown; +}; + +ExceptionHolder::ExceptionHolder(Exception *exception) +: base(new Base(exception)) {} + +ExceptionHolder::ExceptionHolder(const ExceptionHolder &other) +: base(other.base) +{} + +void ExceptionHolder::operator=(const ExceptionHolder &other) +{ + base = other.base; +} + +ExceptionHolder::~ExceptionHolder() +{} + +Exception *ExceptionHolder::exception() const +{ + return base->exception; +} + +void ExceptionStore::setException(const Exception &e) +{ + if (hasException() == false) + exceptionHolder = ExceptionHolder(e.clone()); +} + +bool ExceptionStore::hasException() const +{ + return (exceptionHolder.exception() != 0); +} + +ExceptionHolder ExceptionStore::exception() +{ + return exceptionHolder; +} + +void ExceptionStore::throwPossibleException() +{ + if (hasException() ) { + exceptionHolder.base->hasThrown = true; + exceptionHolder.exception()->raise(); + } +} + +bool ExceptionStore::hasThrown() const { return exceptionHolder.base->hasThrown; } + +} // namespace internal + +#endif //qdoc + +} // namespace QtConcurrent + +QT_END_NAMESPACE + +#endif // QT_NO_EXCEPTIONS +#endif // QT_NO_CONCURRENT |